The overall goal of our research is to understand how people's subjective experiences from exposure to a volatile organic chemical (VOC) are related to (1) the sensory and physiological signals that are elicited by the exposure and to (2) the psychological processes of perception, memory and judgment that mediate between these signals and subjective experience. The research approach uses an information-processing analysis of chemosensory exposure. Our findings to date show the utility of this analysis by demonstrating that people's reports of the effects of chemical exposure depend heavily on their expectancies about the VOC and the exposure situation, and that these reports are modulated by factors such as exposure history and personality type. The proposed research will extend these findings in three directions. Studies conducted under Aim 1 will characterize specific expectancies and mental models that people have for VOC exposure. This information is essential for designing effective communications about VOC exposure. Once the major characteristics of these mental models have been delineated, a second set of studies (Aim 2) will examine how these models are used to incorporate scientific information, beliefs, and hedonic appraisals of odors to make judgments of risk involving VOC exposures. This information is essential for predicting and interpreting the symptoms and health concerns of people in community and work environments when exposure is accompanied by chemosensory cues, such as odor and irritation. Studies conducted wider Aim 3 will try to elucidate the biological pathways that mediate the transformation of chemical signals to subjective reports by correlating breathing patterns and autonomic responses to manipulations of the characteristics features of mental models of VOC exposure. Results from these studies will provide new information about the interplay of psychological and physiological mechanisms underlying acute, adverse responses to chemosensory exposures in everyday environments. The results can assist health professionals in the interpretation and alleviation of adverse response to VOC exposures and can be used to develop cognitive and behavioral interventions to reduce maladaptive autonomic arousal to benign chemosensory cues. This information can also aid public and private organizations in the design of effective risk communication to alleviate public health concerns about VOCs.